天山北坡典型荒漠草地退化特征及其成因

Degradation Characteristics and Causes of Desert Grassland in the Northern Tianshan Mountains

以天山北坡典型荒漠草地为研究对象,利用"点—线—面"的方法,结合景观生态学的原理,以人类活动频繁的城市和农业为主要研究点,设置横竖样带分析典型荒漠草地19 a间的动态变化,进而从自然社会因子角度探讨荒漠草地退化成因。结果表明:1990—2008年间,研究区域荒漠草地面积急剧下降,而农业及其它用地面积增加。同时,荒漠草地覆盖度也明显下降,特别是中覆盖度和高覆盖度草地植被变化较大。从自然因素和社会因素角度分析草地退化原因,起主导作用的是人类的活动和不合理的资源利用导致草地面积减少、覆盖度降低。因此,通过对天山北坡草地退化特征及其成因分析的研究,以期为合理利用、科学管理天然草地提供理论基础。

In this paper, the typical desert grassland in Northern Tianshan Mountains was studied for analyzing pattern dynamic changes of desert grassland between 1990 and 2008 by means of point - line - surface methods. Human activity areas （ city and agriculture） of typical grassland were used as study sites for discussing dynamic changes according to landscape ecologic method. In addition, the causes for grassland degradation were discussed from natural factors to social fac- tors. The result showed that the areas of grassland decreased and those of agricultural and other land use types increased during the last 19 years. At the same time, grassland vegetation coverage also declined from 1990 to 2008, especially middle and high coverage grassland vegetation. In or- der to gain a clear cause of grassland changes, natural and social factors were discussed. The main factors of grassland area decreased and grassland degradation was caused due to human ac- tivities and unreasonable use of grassland resource. Therefore, these results implied that grassland resource reasonable and scientific utilization was the theoretical basis for grassland sustainable de- velopment.